Unit 4 Lesson 7: Biodiversity at Population Levels Flashcards
community
all members of all species in a given area
biodiversity
the variety of life within a species, a community, or an ecosystem.
population
all members of a species in a given area at a given time
As ecosystems are constantly changing, the biodiversity within them can also change.
Some of these changes are temporary.If a food source decreases, the species that eat it may suffer some losses; while others are more long-term, such as if a construction company completely takes down 12 acres of trees to build houses. In this case, the habitat is destroyed, so all the organisms living there either have to move to a new location or perish.
A healthy ecosystem is defined by having a lot of
biological diversity, or biodiversity. This means there is a wide variety of organisms in the ecosystem.
Several other environmental factors can also alter biodiversity. These factors can be biotic or abiotic. These include:
- Severe weather
- Introduction of a new species
- Increased predation
Currently, the factor that has the largest impact on biodiversity in an ecosystem is the
loss of habitat
What is loss of habitat caused by
While this can occur naturally (like if a hurricane knocks down a bunch of trees), the primary cause of deforestation is humans desire to use the land for other purposes.
Impact of loss of habitat on animals
When organisms have no place to live, they cannot survive. Even if there is plenty of food and other resources, without a safe place to sleep at night (or during the day, if applicable), an organism is vulnerable.
More loss of habitat in future
As Earth’s human population continues to increase, the demand for more space for people also increases. It is estimated that by the year 2050, there will be close to 10 billion people on the planet. Each of these people needs a place to live (just like all of the organisms in the tropical rainforest and other ecosystems), so humans cut down trees to make room for new housing developments, shopping malls, and parking lots.
What impact does loss of habitat have on biodiversity
nlike a quick freeze, which might only reduce the biodiversity of an area for a short time, changes like this are often permanent.
benfits of Gentic diversity
Within a populations genetic diversity, having different versions of genes, between individuals can offer stability even in the case of permanent ecological change. When a species has a rich genetic diversity, it is more adaptable, and better able to weather disturbances
What is a population
. That is, a population is a group of individuals of the same species who occupy a certain space at the same time.
if two different groups of red pandas live on the opposite sides of a river are they a population
For instance, if two different groups of red pandas live on the opposite sides of a river, they will be considered two distinct populations. Understanding the range of different populations is important to understanding the likelihood that individuals from one population can move to another, leading to an exchange of genetic material and greater biodiversity.
population connectivity
The exchange of individuals between geographically distinct groups is called population connectivity.
One of the ways that coral reef populations survive those changes is through high population connectivity. But most coral reefs are hundreds, or even thousands of miles apart. How can their populations possibly exchange genetic material?
Most reef fish reproduce by laying eggs. When the eggs hatch, some larvae will find shelter in the reef itself and grow up in the place where they were born. Some of the larvae, however, are carried away from the reef on ocean currents. The ride on an ocean current is a one-way trip. Larvae that find themselves in another reef ecosystem will remain there, reproducing with the local population and contributing to its genetic diversity. New DNA can help reef fish populations become more adaptable to change.
Connectivity helps populations handle some ecological changes, but it can’t help reefs adapt to every kind of disruption. Impact of claimte change
With climate change affecting the entire planet, the oceans are heating up faster than they ever have before. Many species cannot tolerate these increases in temperature, so they migrate to colder waters. Once there, they disrupt the native ecosystem. The new tropical species may have fewer predators in this new territory or they may be better competitors than the natives. Native species may die out or leave the area in search of more resources, this reduces biodiversity.
Additionally, the oceans are becoming warmer due to climate change. Impact on corals
. Corals that form the backbone of coral reefs are unable to tolerate this higher temperature. Over time, the photosynthetic algae living within the coral polyps are expelled, causing the coral to turn white (or bleach). The biodiversity of the reef drastically decreases when this happens. Many of the organisms that lived on the reef must relocate to other areas.
What factors are used to determine how biodiverse an ecosystem is?
Scientists measure how many different types of species are in a given area, as well as how many of each species there are.
How is climate change affecting the biodiversity of coral reefs?
Climate change is causing the oceans to increase in both temperature and acidity. As a result, the photosynthetic algae that live within the coral polyps are being expelled from the coral. This causes the corals to bleach. Without a robust reef to support other organisms, biodiversity decreases.
What is the biggest cause of biodiversity loss? 
Loss of habitat, whether it is caused by climate change, human intervention, or for some other reason, is currently the biggest cause of biodiversity loss. 
Which of the following represents a community?
mice, trees, grasses, deer, birds, rocks, water, and air in a forest
a field mouse eating seeds
all of the mice living in a burrow under leaves
trees, mice, deer, bushes, grasses, and flowers in a forest
Trees, mice, deer, bushes, grasses, and flowers in a forest represent a community because various species are interacting in the same location.
How does the introduction of a new species impact the biodiversity of an ecosystem?
An introduced organism would most likely decrease the biodiversity of an ecosystem. This is because the organisms are often better competitors and/or do not have any local predators. As such, the population size of the introduced species increases dramatically, while that of the native species decreases.
What would be a short-term cause for a decrease in biodiversity?
A hard, but temporary winter freeze of a small pond could cause the biodiversity of that ecosystem to decrease. However, once the water and air temperatures increased, the ice would melt and the pond would spring to life again.
How does an ecosystem compare with a community?
An ecosystem refers to all of the living and nonliving parts of an area, while the community just refers to the living parts.
Many things can decrease the biodiversity of an ecosystem. These include:
- Lack of food
- Lack of space
- Lack of mates
- Increased/decreased temperatures
- Changes in air/water quality
What types of things impact the biodiversity of a community?
There are several things that can impact the biodiversity of a community. These include the introduction of a new predator, lack of food and space, weather events, and changes in environmental conditions.
